Expanding bullets

ABSTRACT

An expanding bullet has a core having a proximal end, a distal end, and a sidewall therebetween. A tip is positioned at the distal end of the core, and has a generally conical distal section, and a generally cylindrical proximal section defining a proximally facing shoulder at their juncture. A jacket having a generally cylindrical proximal portion surrounding at least a portion of the core adjacent its proximal end, and a distal portion that tapers to an open end, the distal portion surrounding the distal portion of the core and the proximal section of the tip, with the distal end of the jacking abutting the shoulder on the tip to form a smooth tapering ogival surface with the tip. The maximum diameter of the tip preferably comprises a substantial portion (preferably at least about 65%) of the diameter of the bullet.

CROSS-REFERENCED APPLICATION

This application claims priority to U.S. provisional application Ser.No. 62/170,118 filed on Jun. 2, 2015. The disclosure of theabove-referenced application is incorporated herein by reference in itsentirety.

FIELD

The present disclosure relates to expanding bullets.

BACKGROUND

This section provides background information related to the presentdisclosure which is not necessarily prior art.

This invention relates to bullets, and in particular to fast-expandinghunting bullets that expand upon impact with a target, creating a moreeffective wound channel.

There is a wide variation in bullet designs to achieve various desirableattributes, such as stable flight and in-target performance. One commonbullet is the hollow point bullet, which typically comprises a core of asoft material such as lead or a lead alloy with a tapering open endedjacket of a harder material, such as copper or a copper alloy. Thisconfiguration allows the bullet to expand upon entering a target. Riflebullets of this type will often also have a tapered polymeric tip toimprove the aerodynamics of the bullet, which can be important forbullets fired at high velocities or over long distances. Typically,because the tip is provided solely for aerodynamics, and has nosignificant function on in-target performance of the bullet, this tip ismade as small as possible while still providing a smooth, aerodynamictransition from the jacket ogive to a tip.

SUMMARY

This section provides a general summary of the disclosure, and is not acomprehensive disclosure of its full scope or all of its features.

Embodiments of the present invention provide expanding hollow pointbullets with improved in-target performance. Bullets of the preferredembodiments more quickly expand in the target, providing moredestruction and energy transfer than conventional hollow point bullets.Generally, a preferred embodiment of the expanding hollow point huntingbullet comprises a core having a proximal end, a distal end, and asidewall therebetween, and a tip having a generally conical distalsection, and a generally cylindrical proximal section defining aproximally facing shoulder at their juncture. A jacket has a generallycylindrical proximal portion surrounding at least a portion of the coreadjacent its proximal end. The jacket also has a distal portion thattapers to an open end. The distal portion surrounds the distal portionof the core as well as the proximal section of the tip, with the distalend of the jacket abutting the shoulder on the tip to form a smoothtapering ogival surface with the tip. The diameter of the tip ispreferably at least about 65% of the diameter of the bullet.

The core is preferably made of a malleable metal or metal alloy, such aslead of a lead alloy. The jacket is preferably made of a harder materialthan the core, such as copper or copper alloy. The tip is preferablymade from a polymeric material, such as polycarbonate.

In some embodiments, the outside diameter of the jacket at the distalend of the core is substantially same as the inside diameter of thejacket at the cylindrical section. The proximal end of the tip abuts thedistal end of the core. The jacket tapers from the proximal end of thedistal section to the distal end of the jacket.

Further areas of applicability will become apparent from the descriptionprovided herein. The description and specific examples in this summaryare intended for purposes of illustration only and are not intended tolimit the scope of the present disclosure.

DRAWINGS

The drawings described herein are for illustrative purposes only ofselected embodiments and not all possible implementations, and are notintended to limit the scope of the present disclosure.

FIG. 1 is a longitudinal cross sectional view of a preferred embodimentof 7 mm expandable hollow point bullet in accordance with a preferredembodiment of this invention;

FIG. 2 is a longitudinal cross sectional view of a preferred embodimentof .30 caliber expandable hollow point bullet in accordance with apreferred embodiment of this invention;

FIG. 3 is a longitudinal cross sectional view of a preferred embodimentof .277 caliber expandable hollow point bullet in accordance with apreferred embodiment of this invention; and

FIG. 4 is a longitudinal cross sectional view of a preferred embodimentof .243 caliber expandable hollow point bullet in accordance with apreferred embodiment of this invention.

Corresponding reference numerals indicate corresponding parts throughoutthe several views of the drawings.

DETAILED DESCRIPTION

Example embodiments will now be described more fully with reference tothe accompanying drawings.

Embodiments of the present invention provide expanding hollow pointbullets with improved in-target performance. Preferred embodiments of abullet in accordance with the principles of this invention are indicatedgenerally as 20, 20′, 20″ and 20′″ in FIGS. 1-4. Each of the bullets 20,20′, 20″ and 20′″ has an overall length A, an ogival length B, a tiplength C, and a maximum tip diameter D. Preferred dimensions for thebullets 20, 20′, 20″ and 20″′ are given in Table 1:

TABLE 1 Preferred Dimensions Overall Ogival Tip Maximum Overall LengthLength Length Tip Diam- Tip Bullet A B C eter D Length E 20 (7 mm) 1.2880.756 0.323 0.190 0.403 20′ (.30 Cal) 1.188 0.692 0.320 0.220 0.400 20″(.270 Cal) 1.272 0.675 0.323 0.190 0.403 20′″ (.243) Cal) 1.143 0.5900.236 0.170 0.316

As shown in FIGS. 1-4. the bullets 20, 20′, 20″ and 20′″ comprise heel22 at the proximal end, a generally cylindrical body 24 adjacent theproximal end, a tapering ogival portion 26 adjacent the distal end, anda tip 28 at the distal end. A cannelure 30 can be formed on the bodygenerally between the generally cylindrical body 24 and the taperingogival portion 26.

The bullets 20, 20′, 20″ and 20″′ each comprise a core 32, having aproximal end 34, a distal end 36, and a sidewall 38 therebetween. Thebullets further comprise a tip 40 having a generally conical distalsection 42, and a generally cylindrical proximal section 44 defining aproximally facing shoulder 46 at the juncture between the distal andproximal sections. A jacket 48 has a generally cylindrical proximalportion 50 surrounding at least a portion of the core 32 adjacent itsproximal end 34. The jacket 48 also has a distal portion 52 that tapersto an open end 54. The distal portion 52 of the jacket 48 surrounds thedistal portion of the core 32 as well as the proximal section 44 of thetip 40, with the distal end of the jacket abutting the shoulder 46 onthe tip to form a smooth tapering ogival surface with the tip.

In contrast to conventional bullets, the tip is relatively larger, i.e.,the ratio of the diameter of the tip to the diameter of the bullet islarger, and the ratio of the tip length to the ogive length is larger.As a consequence, the bullet expands much sooner than conventionalbullets, beginning almost immediately upon impact. This results inincreased disruption to the target, particularly in the initial portionof the wound channel.

Additional dimensions of bullets of the four preferred embodiments shownin FIGS. 1-4, and three comparative examples are given in Table 2, itbeing understood that variations in the dimensions are still within thescope of the invention:

TABLE 2 % Ogive % % area length length Bullet Tip Full Tip coveredcovered covered Bullet Size OD OD Ogive Ogive % dia. by tip by tip bytip .30 Cal 0.3075 0.22 0.692 0.32 71.5 51.2 46.2 26.9 7 mm 0.2835 0.190.756 0.323 67.0 44.9 42.7 25.3 .270 Cal 0.2765 0.19 0.675 0.323 68.747.2 47.9 25.4 .243 Cal 0.2415 0.17 0.59 0.236 70.4 49.6 40.0 20.6 0.223Cal 0.223 0.09 0.45 0.115 40.4 16.3 25.6 0.020 Cal 0.203 0.11 0.38 0.13754.2 29.4 36.1 0.017 Cal 0.172 0.1 0.285 0.14 58.1 33.8 49.1

The maximum diameter of the tip is preferably at least about 65% of thediameter of the bullet, and more preferably at least about 67% of thediameter of the bullet. The maximum cross-sectional area of the tip ispreferably at least about 45% of the cross-sectional area of the bullet.Although it depends upon the shape of the ogival portion, the length ofthe tip is preferably at least about 40% of the length of the ogivalportion.

The core 32 is preferably made of a malleable metal or metal alloy, suchas lead of a lead alloy. The jacket 48 is preferably made of a hardermaterial than the core 32, such as copper or copper alloy. The tip 30 ismade from a polymeric material, such as polycarbonate. The tip 30 couldinclude metal or other filler materials to provide balance or otherdesirable properties.

In some embodiments, the outside diameter of the jacket 48 at the distalend of the core 32 is substantially same as the inside diameter of thejacket at the cylindrical section. The proximal end of the tip 40 abutsthe distal end 36 of the core 32. The jacket tapers from the proximalend of the distal section to the distal end of the jacket.

The action of the bullet with the larger tip is believed related to theenergy of the bullet, which is in part related to the weight of thebullet. Table 3 shows the energy in ft-lbs at 200 yards for selectedbullets, for selected cartridges that have been found to performsatisfactorily with tip configurations in accordance with theembodiments of this invention.

TABLE 3 Energy (ft-lbs) at Bullet Size 200 yards 300 WSM 2541 300 WinMag 2541 30-06 SPRG 2012 308 Win 1867 7 mm Rem Mag 2278 270 Win 2015 270WSM 2333 243 Win 1408

Table 4 shows the weight ranges and a preferred weight range for thefour calibers of the four preferred embodiment, and for threecomparative bullets. The bullets of the preferred embodiments preferablyhave a weight of between about 85 grains and about 185 grains, and morepreferably a weight of between about 95 grains and about 150 grains. Thebullets of the preferred embodiment are preferably loaded intocartridges that provide sufficient energy at the point of impact so thatwith the larger tip, the bullet will begin expanding almost immediatelyafter initial impact. For example bullets having the 200 yard energiesshown in Table 3, generally will have sufficient energy at the point ofimpact for most hunting applications to exhibit enhanced expansion fromthe enlarged tip.

TABLE 4 Typical Weight Preferred Embodiment Bullet Size Range (Grains)Weight (Grains) 7 mm 140-160 140 0.30 Cal 120-220 150 0.270 Cal 130-150130 0.243 Cal 55-95  95 0.223 Cal 35-77 N/A

It is believed by the inventors that the tip configurations inaccordance with the principles of this invention expand faster andprovide larger wound channels because less of the bullet's energy isdepleated opening the jacket. This is reflected in the fact that lessenergy is required to form the jacket in the die because the jacket doesnot have to be deformed as much to form an aerodynamic tip.

The foregoing description of the embodiments has been provided forpurposes of illustration and description. It is not intended to beexhaustive or to limit the disclosure. Individual elements or featuresof a particular embodiment are generally not limited to that particularembodiment, but, where applicable, are interchangeable and can be usedin a selected embodiment, even if not specifically shown or described.The same may also be varied in many ways. Such variations are not to beregarded as a departure from the disclosure, and all such modificationsare intended to be included within the scope of the disclosure.

Example embodiments are provided so that this disclosure will bethorough, and will fully convey the scope to those who are skilled inthe art. Numerous specific details are set forth such as examples ofspecific components, devices, and methods, to provide a thoroughunderstanding of embodiments of the present disclosure. It will beapparent to those skilled in the art that specific details need not beemployed, that example embodiments may be embodied in many differentforms and that neither should be construed to limit the scope of thedisclosure. In some example embodiments, well-known processes,well-known device structures, and well-known technologies are notdescribed in detail.

What is claimed is:
 1. An expanding rifle bullet, comprising: a corehaving a proximal end, a distal end, and a sidewall therebetween; a tiphaving a generally conical distal section, and a generally cylindricalproximal section defining a proximally facing shoulder at theirjuncture; a jacket having a generally cylindrical proximal portionsurrounding at least a portion of the core adjacent its proximal end,and a distal portion that tapers to an open end, the distal portionsurrounding the distal portion of the core, and the proximal section ofthe tip, with the distal end of the jacking abutting the shoulder on thetip to form a smooth tapering ogival surface with the tip, the maximumdiameter of the tip is at least about 65% of the diameter of the bullet,the bullet weighing between about 85 grains and about 185 grains.
 2. Theexpanding rifle bullet according to claim 1 wherein the bullet weighsbetween about 95 grains and about 150 grains.
 3. The expanding riflebullet according to claim 1 wherein the maximum diameter of the tip isat least about 67% of the diameter of the bullet.
 4. The expanding riflebullet according to claim 1 wherein the maximum cross-sectional area ofthe tip is at least about 45% of the cross-sectional area of the bullet.5. The expanding rifle bullet according to claim 1 wherein the maximumcross-sectional area of the tip is at least about 50% of thecross-sectional area of the bullet.
 6. The expanding rifle bulletaccording to claim 1 wherein the exposed length of the tip comprises atleast about 40% of the length of the ogive.
 7. The expanding riflebullet according to claim 6 wherein the exposed length of the tipcomprises at least about 42% of the length of the ogive.
 8. Theexpanding rifle bullet according to claim 1 wherein the exposed lengthof the tip comprises at least about 20% of the length of the bullet. 9.The expanding rifle bullet according to claim 8 wherein the exposedlength of the tip comprises at least about 25% of the length of thebullet.
 10. The expanding bullet according to claim 1 wherein the coreis made of a malleable metal or metal alloy.
 11. The expanding riflebullet according to claim 10 wherein the core is made of lead of a leadalloy.
 12. The expanding rifle bullet according to claim 1 wherein thejacket is made of a harder material than the core.
 13. The expandingrifle bullet according to claim 12 wherein the jacket is made of copperor copper alloy.
 14. The expanding rifle bullet according to claim 1wherein the jacket is made of copper or copper alloy.
 15. The expandingrifle bullet according to claim 1 wherein the tip is made of a polymericmaterial.
 16. The expanding rifle bullet according to claim 1 whereinthe outside diameter of the jacket at the distal end of the core issubstantially same as the inside diameter of the jacket at thecylindrical section.
 17. The expanding rifle bullet according to claim 1wherein the proximal end of the tip abuts the distal end of the core.18. The expanding rifle bullet according to claim 1 wherein thethickness of the jacket tapers from the proximal end of the distalsection to the distal end of the jacket.
 19. An expanding rifle bullet,comprising: a malleable metallic core having a proximal end, a distalend, and a generally cylindrical sidewall therebetween; a tip having agenerally conical distal section, and a generally cylindrical proximalsection defining a proximally facing shoulder at their juncture; ajacket having a generally cylindrical proximal portion surrounding atleast a portion of the core adjacent its proximal end, and a distalportion that tapers to an open end, the distal portion surrounding thedistal portion of the core, and the proximal section of the tip, withthe distal end of the jacking abutting the shoulder on the tip to form asmooth tapering ogival surface with the tip, the area of the open distalend of the jacket comprising at least 45% of the area of cross sectionalarea of the proximal section of the jacket, the bullet having a weightof between about 85 grains and 185 grains.
 20. The expanding riflebullet according to claim 19 wherein the bullet has a weight of betweenabout 95 grains and about 150 grains.